Self-healing Performance of Composite Coatings Prepared by Phosphating and Cerium Nitrate Post-sealing
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2015年第4期
论文作者：林碧兰 LU Jintang
文章页码：813 - 817
摘 要：The phosphated and cerium nitrate post-sealed galvanized steel was firstly scratched to expose zinc layer and then placed in neutral salt spray（NSS） chamber for different durations. The microstructure and compositions of the scratches were investigated using SEM and EDS. The phases of the corrosion products were examined through XRD. The self-healing mechanism of the composite coatings was discussed. The experimental results show that the composite coatings have an excellent corrosion resistance. The corrosion products increase with corrosion time and finally cover the whole scratch. They contain phosphorous, cerium, oxygen, chloride and zinc, and are fine needle and exceedingly compact. The composite coatings are favorable self-healing. During corrosion, the self-healing ions such as Ce3+, Ce4+, PO3-+4, Zn2 in the composite coatings were dissolved, migrated, recombined, and covered the exposed zinc, impeding zinc corrosion. The self-healing process of the scratches on the composite coatings can be divided into three stages, about 2 h, 4 h, and 24 h, respectively.
林碧兰1，LU Jintang2
1. School of Material Science and Engineering, Xiamen University of Technology2. School of Material Science and Engineering, South China University of Technology
摘 要：The phosphated and cerium nitrate post-sealed galvanized steel was firstly scratched to expose zinc layer and then placed in neutral salt spray（NSS） chamber for different durations. The microstructure and compositions of the scratches were investigated using SEM and EDS. The phases of the corrosion products were examined through XRD. The self-healing mechanism of the composite coatings was discussed. The experimental results show that the composite coatings have an excellent corrosion resistance. The corrosion products increase with corrosion time and finally cover the whole scratch. They contain phosphorous, cerium, oxygen, chloride and zinc, and are fine needle and exceedingly compact. The composite coatings are favorable self-healing. During corrosion, the self-healing ions such as Ce3+, Ce4+, PO3-+4, Zn2 in the composite coatings were dissolved, migrated, recombined, and covered the exposed zinc, impeding zinc corrosion. The self-healing process of the scratches on the composite coatings can be divided into three stages, about 2 h, 4 h, and 24 h, respectively.
关键词：
